[Help please]Bios wont boot after restart

Hi everyone, I have a very VERY strange problem...
Just to let you know, I am not a complete noob, I have built numerous systems and understand the technical PC language To the point:
Recently I have upraged from ASUS P5QL to P5QL PRO (not much of a difference between these two but I got it for free so might as well install it in my system)
From 3GB of mixed DDR2 ram to 2xcrucial ballistix 1GB 800mh/z and 2xcrucial ballistix 1066mh/z, from Core2Due E6600 to a Core2Duo E7500 (OC'ed to 3.7Gh/z stable)
The rest of the specs are: "High Power Plus" 500W PSU, nVIDIA GTX460 from Zodiac and 2 HDD's (which I dont think is relevant)

Problem is: when I turn of the computer and try to turn it back on again then sometimes it does turn on but the screen remains on stand-by and the mobo speaker does not go off. To fix this I have to either turn off the PSU for couple of seconds (with the help of the magic little on/off button at the back) or take out 3 ram chips leaving me with one, after that the system boots with default bios settings, then it check everything and then again it restarts itself and asks me if I want to run default settings (F2) or if I preffer to go into Bios and keep my OC (F1).

It's not much of a problem as I can still boot my PC without much of a problem but it is rather annoying.
Please help Thank you

Remove either the 2 x DDR2-800 or the 2 x DDR2-1066, and leave the remaining two modules installed in the yellow DIMM slots for a dual-channel config. You might also want to post what the SPD timings and voltage are for both sets of RAM at their rated frequencies. Or if you know what the rated timings and voltage are for each set, then manually adjust the four primary timings (leave all sub-timings on Auto) and the DRAM voltage accordingly.

Slot 1 is the 1066 and Slot 2 is the 800
They are both paired up in a way: yellow = 1066 and black = 800
I have set up the voltage to 1.9V, and can you tell me what causes the problem please?
Thanks for the response

Assuming a FSB of 336MHz (336 x 11 = 3.7GHz), what's the current DRAM frequency and FSB : DRAM ratio?

FSB: 327 (I forgot that I have let it down for a little bit for testing purposes)
Strap to North Bridge: 333
DDR2-786
Timing on auto

Well w/ the FSB at 327MHz, and the RAM on the 333 strap using the 5:6 FSB : DRAM ratio = DDR2-784, temporarily remove the DDR2-800 from slots 2 and 4. Keep the remaining DDR2-1066 in slots 1 and 3, adjust the four primary timings to 4-4-4-12-2T (Command Rate), and the DRAM voltage to 2.2V.

Ok, but does that mean that I have to get rid of two chips leaving me with only 2GB of ram? Or after doing as you said I am supossed to clip in the other two chips and set their timings as well?

Just run w/ the two modules for the time being, first making sure Memtest86+ passes without errors, then making sure you don't still have the issues you originally posted about. If no problems are found w/ the DDR2-1066, substitute them for the DDR2-800, leaving the timings the same but lowering the DRAM voltage to 2.0V. If no problems are found w/ those modules, then reinstall them along w/ the DDR2-1066, but bump the DRAM voltage back up to 2.2V. Be aware that w/ the DRAM voltage set to 2.2V, that's 0.2V higher than the what the DDR2-800 is rated at 400MHz and 2.0V.

The problem seemed to be within the rams, mixing 800 mhz modules with 1066 ones seemed to be the case, or the 1066 were broken, either way my PC has been runing good since then